Among other things, the investigators discovered that searching for one ingredient (harmless on its own), or adding it to your cart, would lead Amazon to show you that other customers bought the other incendiary components. For the sake of good taste, I won’t list the ingredients here, but the examples they gave were the ingredients for thermite and black powder.

Keep in mind, for some of these there’s likely a perfectly reasonable explanation. Thermite is often used in welding, so it’s not out of the question that someone bought the ingredients to use innocently at one point.

Likewise, the explosive black powder ingredients the investigators mention are used in pyrotechnics such as fireworks or rocket launches, as well as industrial work. So there’s a strong chance customers who bought the ingredients together did so with benign intent.

Still, Amazon appears to be taking the possibility seriously. A spokesperson told TNW:

All products sold on Amazon must adhere to our selling guidelines and we only sell products that comply with UK laws. In light of recent events, we are reviewing our website to ensure that all these products are presented in an appropriate manner. We also continue to work closely with police and law enforcement agencies when circumstances arise where we can assist their investigations